1. Field of the Invention
This invention relates to an artificial knee joint, and more particularly to an artificial knee joint having a knee angle that is formed between a residual thigh and a prosthetic lower leg and that is no smaller than a threshold angle.
2. Description of the Related Art
Referring to FIG. 1, a conventional artificial knee joint includes a linkage 10, a knee seat 11 connected to a residual thigh, and a pneumatic cylinder for dampening downward movement of the knee seat 11. The pneumatic cylinder includes a piston rod 12 and a cylinder body 13 connected to a prosthetic lower leg. When the user walks down a slope, the center of gravity of the user may move rearwardly and downwardly within a very short time. If this occurs, it is possible for the piston rod 12 to be moved instantly and rapidly relative to the cylinder body 13, which may results in the user falling down.